固相微萃取法的應用包括：(I) 使用HS-SPME結合氣體層析儀來分析水中除蟲菊酯殺蟲劑之最佳化條件探討(II) 應用頂空及薄膜保護式固相微萃取結合GC/Flameless SCD來偵測與定量奶品中含硫化物

Abstract

Part I. A method for analyzing of pyrethroid pesticides in water solution by solid-phase microextraction (SPME) and gas chromatography (GC) is described. Five kinds of pyrethroid pesticides, including Bifenthrin, λ-Cyhalothrin, Permethrin, Cyfluthrin and Deltamethrin were determined. These were once widely used to control insects for crop production in Taiwan. Experimental design was achieved by using 65 μm polydimethylsiloxane-divinylbenzene (PDMS-DVB) SPME fiber and used the HS-SPME mode to extract the pyrethroid pesticides from water sample and determined by GC with ECD . The influence of the extraction process was also studied and optimized. HS-SPME experimental parameters such as extraction temperature, extraction time, salt concertation and pH values were investigated and optimized. From our experimental results show that the optimized conditions were : 60 min extraction at 100℃, 1% NaCl content and pH 4 for pyrethroid pesticides in water solution. Part II. Many volatile compounds generated during the thermal processing of milk have been related to stable, sulfurous and cooked flavor in milk. Volatile sulfides were derived from the sulfhydryl groups of β-lactoglobulin for the “cabbagey” and “cooked” flavor in heated milk; however, their analysis has been a challenge due to their high reactivity, high volatility, and low sensory threshold (sensitive limit). To quantitative determination of volatile sulfur compounds (VSCs) in milk by headspace (HS-SPME) and hollow fiber membrane-protected solid-phase microextraction (HFM-SPME) with Gas chromatography-Flameless Sulfur chemiluminescence detection (GC-Flameless SCD) was investigated in this study. This method provides a very simple and fast technique. There are three parts to study in this research, including (1) The sulfur compounds generated during the thermal processing of skim and whole milk. (2) Calibration curves were established from standard solution for methanethiol (MeSH), dimethyl sulfide (DMS), dimethyl disulfide (DMDS) and dimethyl trisulfide (DMDS). (3) HS-SPME experimental parameters such as extraction temperature, extraction time, salt concertation and pH value were investigated. From our experimental results, the concentrations of sulfur compounds in skim milk were 3.06~4.11 ng/mL for MeSH, 0.05 ng/mL for DMS, 0.01~0.02 ng/mL for DMDS, 0.01 ng/mL for DMTS and the concentrations of sulfur compounds in whole milk were for 0.45 ng/mL MeSH, 0.08~0.11 ng/mL for DMS, 0.02 ng/mL for DMDS, 0.01 ng/mL for DMTS, respectively.